US9549818B2 - Pneumatically power-assisted tavi delivery system - Google Patents

Abstract

A delivery device for a collapsible prosthetic heart valve may include an operating handle and a catheter assembly. The handle may include a housing, a piston cylinder, a piston longitudinally slidable within the piston cylinder, the piston and the piston cylinder together defining at least one pressure chamber, a deployment actuator coupled to the housing and rotatable relative thereto, and a pneumatic switch adapted to provide a pressurized fluid to the pressure chamber to apply a longitudinal force to the piston. The catheter assembly may include a first shaft around which a valve-receiving compartment is defined, the first shaft being operatively connected to the housing, and a distal sheath operatively connected to the piston, the distal sheath being moveable between a closed condition covering the compartment and an open condition uncovering the compartment. Longitudinal movement of the piston may move the distal sheath between the closed and open conditions.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of the filing date of U.S. Provisional Patent Application No. 61/903,046 filed Nov. 12, 2013, the disclosure of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention is related to prosthetic heart valve replacement, and more particularly to devices, systems, and methods for transapical and transcatheter delivery of collapsible prosthetic heart valves.

Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery.

Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve must first be collapsed or crimped to reduce its circumferential size.

When a collapsed prosthetic valve has reached the desired implant site in the patient (e.g., at or near the annulus of the patient's heart valve that is to be replaced by the prosthetic valve), the prosthetic valve can be deployed or released from the delivery apparatus and re-expanded to full operating size. For balloon-expandable valves, this generally involves releasing the entire valve, assuring its proper location, and then expanding a balloon positioned within the valve stent. For self-expanding valves, on the other hand, the stent automatically expands as the sheath covering the valve is withdrawn.

BRIEF SUMMARY OF THE INVENTION

Delivery devices for a collapsible prosthetic heart valve and methods of delivering a collapsible prosthetic heart valve using same are aspects of the invention. In addition, any device having one or more of the following features and used in the transcatheter delivery of a collapsible heart valve are the specific aspects of the invention.

A delivery device for a collapsible prosthetic heart valve may include an operating handle and a catheter assembly. The operating handle may include a housing defining a movement space therein, a piston cylinder disposed within the movement space, a piston slidable in a longitudinal direction within the piston cylinder, the piston and the piston cylinder together defining at least one pressure chamber, a deployment actuator coupled to the housing and rotatable relative to the housing, and a pneumatic switch in fluid communication with the pressure chamber, the pneumatic switch adapted to provide a pressurized fluid to the pressure chamber to apply a force to the piston in the longitudinal direction.

The catheter assembly may include a first shaft around which a compartment is defined, the first shaft being operatively connected to the housing, the compartment being adapted to receive the valve in an assembled condition, and a distal sheath operatively connected to the piston, the distal sheath being moveable between a closed condition covering the compartment and an open condition uncovering the compartment for deployment of the valve. Movement of the piston in the longitudinal direction in the piston cylinder may move the distal sheath between the closed condition and the open condition.

The piston cylinder may include a proximal piston cylinder and a distal piston cylinder, the piston and the proximal piston cylinder together defining a proximal pressure chamber and the piston and the distal piston cylinder together defining a distal pressure chamber. The first shaft may be attached to the distal sheath and operatively connected to the piston, the catheter assembly also including an outer shaft connecting the housing to the compartment and at least partially surrounding the first shaft. The piston cylinder may be a distal piston cylinder surrounding a distal end of the piston. The catheter assembly may also include an outer shaft attached to the distal sheath and operatively connected to the piston, the outer shaft at least partially surrounding the first shaft. The piston cylinder may be a proximal piston cylinder surrounding a proximal end of the piston.

The deployment actuator may be a knob rotatable about a central axis that extends parallel to the longitudinal direction. Rotation of the deployment actuator in a first direction may move the piston proximally in the longitudinal direction, and rotation of the deployment actuator in a second direction opposite the first direction may move the piston distally in the longitudinal direction. The piston may be a threaded rod in threaded engagement with the deployment actuator.

The operating handle may also include a coupling assembly rotationally fixed to the deployment actuator, the coupling assembly having an engaged position in which rotation of the deployment actuator moves the threaded rod in the longitudinal direction, and a disengaged position in which rotation of the deployment actuator does not move the threaded rod in the longitudinal direction. The coupling assembly may include a split nut having a plurality of threaded split nut portions, the split nut portions each being linearly slidable away from one another and away from the threaded rod, the split nut having an engaged position in which threads of the split nut portions are engaged with the threaded rod and a disengaged position in which the threads of the split nut portions do not engage the threaded rod.

Rotation of the deployment actuator in a first direction may actuate the pneumatic switch and may provide the pressurized fluid to the pressure chamber. The operating handle may also include a toggle guide moveable in the longitudinal direction relative to the deployment actuator, and rotation of the deployment actuator in the first direction may cause movement of the toggle guide in the longitudinal direction away from the deployment actuator, thereby actuating the pneumatic switch.

The piston cylinder may include a proximal piston cylinder and a distal piston cylinder, the piston and the proximal piston cylinder together defining a proximal pressure chamber and the piston and the distal piston cylinder together defining a distal pressure chamber. Rotation of the deployment actuator in a first direction may actuate the pneumatic switch and may provide the pressurized fluid to the proximal pressure chamber, and rotation of the deployment actuator in a second direction opposite the first direction may actuate the pneumatic switch and may provide the pressurized fluid to the distal pressure chamber.

A method of delivering a collapsible prosthetic heart valve in a patient may include providing a delivery device having a catheter assembly and an operating handle, the catheter assembly including a compartment adapted to receive the valve in an assembled condition, the operating handle including a housing defining a movement space therein, a piston cylinder disposed within the movement space, a piston slidable in first and second longitudinal directions within the piston cylinder, the piston and the piston cylinder together defining at least one pressure chamber, a deployment actuator coupled to the housing and rotatable relative to the housing, and a pneumatic switch in fluid communication with the pressure chamber.

The method may also include loading the valve into the compartment of the catheter assembly and covering the compartment and the valve with a distal sheath of the catheter assembly, and inserting the catheter assembly into the patient so that the valve is positioned at a target location within the patient. The method may further include actuating the pneumatic switch, thereby providing a pressurized fluid to the pressure chamber and applying a force to the piston in the first longitudinal direction, and opening or closing the compartment by rotating the deployment actuator to move the piston of the operating handle in the first longitudinal direction.

The piston cylinder may include a proximal piston cylinder and a distal piston cylinder, the piston and the proximal piston cylinder together defining a proximal pressure chamber and the piston and the distal piston cylinder together defining a distal pressure chamber. The step of opening or closing the compartment may include opening the compartment by rotating the deployment actuator in a first rotational direction to move the piston of the operating handle in the first longitudinal direction. The method may also include actuating the pneumatic switch, thereby providing a pressurized fluid to the distal chamber and applying a force to the piston in the second longitudinal direction, and closing the compartment by rotating the deployment actuator in a second rotational direction to move the piston of the operating handle in the second longitudinal direction.

The catheter assembly may also include a first shaft around which the compartment is defined and an outer shaft connecting the housing to the compartment and at least partially surrounding the first shaft. The first shaft and the distal sheath may be operatively connected to the piston, the piston cylinder may be a distal piston cylinder surrounding a distal end of the piston, and the step of actuating the pneumatic switch may provide a pressurized fluid to the pressure chamber and may apply a force to the piston in the second longitudinal direction.

The catheter assembly may also include a first shaft around which the compartment is defined and an outer shaft connecting the carriage assembly to the distal sheath and at least partially surrounding the first shaft. The first shaft may be fixedly connected to the housing, the distal sheath may be operatively connected to the piston, the piston cylinder may be a proximal piston cylinder surrounding a proximal end of the piston, and the step of actuating the pneumatic switch may provide a pressurized fluid to the pressure chamber and may apply a force to the piston in the first longitudinal direction.

The deployment actuator may be a knob rotatable about a central axis that extends parallel to the first and second longitudinal directions. The piston may be a threaded rod in threaded engagement with the deployment actuator, and the deployment actuator may be longitudinally constrained relative to the housing. The actuating of the pneumatic switch to provide the pressurized fluid to the pressure chamber may be effected by the rotation of the deployment actuator in the first rotational direction.

The operating handle may also include a toggle guide moveable in the first and second longitudinal directions relative to the deployment actuator. The rotation of the deployment actuator in the first rotational direction may cause movement of the toggle guide in the first longitudinal direction away from the deployment actuator, thereby effecting the actuating of the pneumatic switch. The target location may be the native aortic annulus of the patient. The inserting step may include inserting the distal sheath of the catheter assembly through the apex of the heart of the patient. The inserting step may include inserting the distal sheath of the catheter assembly through a femoral artery of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention will now be described with reference to the appended drawings. It is to be appreciated that these drawings depict only some embodiments of the invention and are therefore not to be considered limiting of its scope.

FIG. 1A is a top view of a transapical delivery device for a collapsible prosthetic heart valve;

FIG. 1B is a top view of the delivery deviceFIG. 1A, shown with the compartment unsheathed;

FIG. 1C is a partial longitudinal cross-section of the distal portion of the catheter assembly ofFIG. 1A;

FIG. 2A is a top view of the operating handle ofFIG. 1A with the housing partially removed to show the interior thereof;

FIG. 2B is a top view of the piston assembly ofFIG. 2A;

FIG. 2C is a longitudinal cross-section of the operating handle ofFIG. 1A;

FIG. 3A is a longitudinal cross-section of an operating handle for a transfemoral delivery device for a collapsible prosthetic heart valve;

FIG. 3B is a top view of the distal portion of a transfemoral catheter assembly that may be operated by the operating handle ofFIG. 3A, the distal sheath of the assembly being partially removed to show the interior thereof;

FIG. 4A is an exploded perspective view of a deployment actuator assembly that can be integrated into the operating handle ofFIG. 1A orFIG. 3A;

FIG. 4B is an enlarged perspective view of a portion of the deployment actuator assembly ofFIG. 4A;

FIG. 4C is a longitudinal cross-section of the deployment actuator assembly ofFIG. 4A, with the deployment actuator shown in threaded engagement with the threaded rod;

FIG. 4D is a longitudinal cross-section of the deployment actuator assembly ofFIG. 4A, with the deployment actuator shown disengaged from the threaded rod;

FIG. 5A is a side view of a smart wheel assembly that can be integrated into the operating handle ofFIG. 1A orFIG. 3A;

FIG. 5B is a longitudinal cross-section of the smart wheel assembly ofFIG. 5A; and

FIGS. 5C and 5D are exploded perspective views of the smart wheel assembly ofFIG. 5A.

DETAILED DESCRIPTION

There is a need for further improvements to the devices, systems, and methods for transcatheter delivery of collapsible prosthetic heart valves, and in particular, self-expanding prosthetic heart valves.

Embodiments of the present invention may include an operating handle having proximal and distal pressure chambers that are adapted to provide either a distal or proximal force assist during deployment of a prosthetic valve, such that the amount of force required of a user to rotate a deployment actuator knob of the operating handle is reduced, particularly during resehathing of a prosthetic valve after it has been partially expanded in a patient, which is typically resisted by significant friction (e.g., 6-20 lbs.) between a distal sheath and the prosthetic valve. In some embodiments, the operating handles described herein may provide 8-10 lbs. of distal or proximal force assist in the longitudinal direction of the handle.

As used herein, the terms “proximal” and “distal” are to be taken as relative to a user using the disclosed delivery devices. “Proximal” is to be understood as relatively close to the user and “distal” is to be understood as relatively farther away from the user. Also as used herein, the terms “generally,” “substantially,” and “about” are intended to mean that slight deviations from absolute are included within the scope of the term so modified.

Referring now toFIGS. 1A-1C to illustrate the structure and function of the present invention, an exemplarytransapical delivery device10 for a collapsible prosthetic heart valve (or other types of self-expanding collapsible stents) has acatheter assembly16 for delivering the heart valve to and deploying the heart valve at a target location, and anoperating handle20 for controlling deployment of the valve from the catheter assembly. Thedelivery device10 extends from aproximal end12 to anatraumatic tip14 at the distal end of thecatheter assembly16. Theatraumatic tip14 may be formed from or may include a radiopaque material to enable the tip to be visible under fluoroscopy during a deployment procedure.

Thecatheter assembly16 is adapted to receive a collapsible prosthetic heart valve (not shown) in acompartment23 defined between atubular support shaft19 and adistal sheath24 that surrounds the support shaft. Thesupport shaft19 is fixedly coupled to the operating handle20 by anouter shaft22, the proximal end of which is fixedly connected to the operating handle and the distal end of which is fixedly connected to the support shaft. Thedistal sheath24 is fixedly coupled to aninner shaft26 by theatraumatic tip14. Theinner shaft26 extends from theautraumatic tip14 through thesupport shaft19 and through the operatinghandle20. Thedistal sheath24,atraumatic tip14, andinner shaft26 are together slidable relative to thesupport shaft19,outer shaft22, and operatinghandle20, such that the distal sheath can selectively cover or uncover thecompartment23. The connection of thedistal sheath24 to theatraumatic tip14 thus enables theinner shaft26 to control the movement of the distal sheath both proximally and distally.

Thesupport shaft19 extends between a pair of spacedretainers25 and27 affixed thereto and defining the ends of thecompartment23. A collapsible prosthetic valve may be assembled around thesupport shaft19 and between theretainers25 and27 in thecompartment23. Theretainer25 may haverecesses80 therein that are adapted to hold corresponding retention members of the valve.

Thedistal sheath24 is affixed at its distal end to theatraumatic tip14, and itsproximal end29 terminates at or near theretainer27 when the distal sheath is fully covering thecompartment23, as shown inFIG. 1C. The distal end of theouter shaft22 terminates at or near the retainer and preferably abuts theproximal end29 of thedistal sheath24 when the distal sheath is in the proximalmost position, as shown inFIG. 1C. Theproximal end29 of thedistal sheath24 is spaced apart from theretainer27 when thecompartment23 is at least partially uncovered, as shown inFIG. 1B.

Thedelivery device10 may include measurement markings81 (FIG. 1B) thereon to assist the user in determining the location or depth of portions of the device with respect to the aortic annulus or the apex of the heart. One or more of themarkings81 may be located on thedistal sheath24, so that the user can determine how far the distal sheath has moved relative to its initial position during deployment of a valve. One or more of themarkings81 may be located on thesupport shaft19 at the anticipated location of the leaflets of the prosthetic aortic valve, so that the user can know where the leaflets are relative to the native aortic annulus during deployment of the valve. One or more of themarkings81 may be located on theouter shaft22, so that the user can determine how far theatraumatic tip14 has been inserted into a patient before uncovering of thecompartment23 has begun. Each of themeasurement markings81 may include a material selected from the group consisting of a polymer, gold, platinum, nitinol, and combinations thereof, or one or more other metallic or polymer materials, and such markings may be radiopaque, i.e., the markings may be visible to the user under fluoroscopy.

The operatinghandle20 is adapted to control deployment of a prosthetic valve located in thecompartment23 by permitting a user to selectively slide theinner shaft26 and the attacheddistal sheath24 distally or proximally relative to thesupport shaft19, thereby respectively uncovering or covering the compartment with the distal sheath.

Referring toFIGS. 2A-2C, the proximal end of theouter shaft22 is connected in substantially fixed relationship to anouter housing30 of theoperating handle20, and a location near the proximal end of theinner shaft26 is fixedly connected to a piston in the form of a threaded rod that is translatable along a longitudinal axis of the handle housing. As a result of the structure, a user can selectively slide theinner shaft26 relative to theouter shaft22 by translating the threadedrod36 relative to thehousing30. The threadedrod36 has an unthreadedproximal end38 with anend surface38a, and an unthreadeddistal end39 with anend surface39a. The threadedrod36 preferably is longer than the anticipated maximum travel distance of the distal sheath24 (e.g., at least about 50 mm), such that the threadedrod36 does not fully disengage from the deployment actuator21 (described below) during unsheathing or resheathing of the prosthetic valve.

As shown inFIG. 2C, theinner shaft26 may extend through the threadedrod36, and the proximal end of the inner shaft may extend through thehousing30 beyond theproximal end12 thereof. Ahemostasis valve28 attached to the proximal end of the inner shaft26 (FIG. 1B) may permit removal of air from thedevice10 through the inner shaft before deployment of the valve.

Thehandle housing30 includes atop portion30a(FIG. 1A) and abottom portion30b(FIG. 2A). The top andbottom portions30aand30bmay be individual components joined to one another. Collectively, the top andbottom portions30aand30bdefine an elongated space34 (FIG. 2C) along the longitudinal axis of thehousing30 in which apiston assembly40 including the threadedrod36 and proximal anddistal piston cylinders41 and42 (described below) may be disposed.

Thehandle housing30 further defines apocket37 that extends transversely through thetop portion30aandbottom portion30bfor receiving adeployment actuator21. Thedeployment actuator21 is internally threaded and is threadedly engaged with the threadedrod36. Thepocket37 is sized and shaped to receive thedeployment actuator21 with minimal clearance, such that the location of the deployment actuator remains substantially fixed relative to thehousing30 as it is rotated about the threadedrod36.

Rotation of thedeployment actuator21 in one direction (either clockwise or counterclockwise depending on the orientation of the threads on the threaded rod36) causes the threaded rod to move proximally within thepiston cylinders41,42. Similarly, rotation of thedeployment actuator21 in the opposite direction causes the threadedrod36 to move distally within thepiston cylinders41,42.

The proximal anddistal piston cylinders41 and42 together define an enlarged bore35 (FIG. 2C) that is sized to slidingly receive the threadedrod36. The enlarged bore35 has an inner diameter slightly larger than the outer diameter of the threadedrod36. For example, theenlarged bore35 may have an inner diameter of about 0.5 inches or about 0.75 inches. Each of thepiston cylinders41,42 has an open end adjacent thedeployment actuator21 and a closed end remote from the deployment actuator. The enlarged bore35 preferably permits the threadedrod36 to travel a distance that is at least as long as the anticipated length of the prosthetic valve to be delivered (e.g., at least about 50 mm), such that thedistal sheath24 can be fully advanced from around the prosthetic valve.

Each of the proximal anddistal piston cylinders41, includes arespective pressure chamber43,44 within a portion of theenlarged bore35. Theproximal pressure chamber43 is defined by the closed end of theproximal piston cylinder41 and theend surface38aof the threadedrod36. A proximal seal45 (e.g., an o-ring) provides a seal between theunthreaded end38 of the threadedrod36 and the inner surface of theproximal piston cylinder41, thereby preventing leakage from theproximal pressure chamber43. Theproximal seal45 may be formed contiguously with theproximal surface38aof the threadedrod36, or it may be a separate component that extends within a groove around theunthreaded end38 of the threaded rod. A further seal47 (e.g., an o-ring) in the closed end of thepiston cylinder41 provides a seal with theinner shaft26.

Thedistal pressure chamber44 is defined by the closed end of thedistal piston cylinder42 and theend surface39aof the threadedrod36. A distal seal46 (e.g., an o-ring) provides a seal between theunthreaded end39 of the threadedrod36 and the inner surface of thedistal piston cylinder42, thereby preventing leakage from thedistal pressure chamber44. Thedistal seal46 may be formed contiguously with thedistal surface39aof the threadedrod36, or it may be a separate component that extends within a groove around theunthreaded end39 of the threaded rod. An additional seal48 (e.g., an o-ring) in the closed end of thepiston cylinder42 provides a seal with theinner shaft26.

An outer surface of theinner shaft26 may be sealed against an inner surface of a lumen extending longitudinally within the threadedrod36, by a metallic weld, press-fit interference, or by an adhesive extending between the inner shaft and the lumen of the threaded rod, for example. This seal between theinner shaft26 and the threadedrod36 prevents leakage between theproximal pressure chamber43 and thedistal pressure chamber44 through the lumen of the threaded rod.

A pneumatic switch90 (FIG. 1A) may be in fluid communication with the proximal anddistal pressure chambers43,44 via lengths oftubing91,92. Thetubing91 may extend between thepneumatic switch90 and aproximal port93 in theproximal pressure chamber43, and thetubing92 may extend between the pneumatic switch and adistal port94 in thedistal pressure chamber44. The proximal anddistal ports93,94 may be oriented toward any direction. For example, theproximal port93 is facing proximally inFIGS. 2A and 2B and distally inFIG. 2C.

Thepneumatic switch90 may be movable to a first position that provides pressurized fluid (e.g., air) from a pressure source (not shown) to theproximal pressure chamber43, while venting thedistal pressure chamber44 to atmospheric pressure, thereby creating a pressure differential between the proximal and distal pressure chambers. For example, pressurized air can be provided to theproximal pressure chamber43 at a pressure of about 40 psig to about 50 psig, whereas the pressure in thedistal pressure chamber44 can be reduced to atmospheric pressure.

In other examples, any other pressure differential between theproximal pressure chamber43 and thedistal pressure chamber44 may be used. It is not required that thedistal pressure chamber44 be vented to atmospheric pressure when theproximal pressure chamber43 is pressurized, so long as the pressure in the proximal pressure chamber exceeds the pressure in the distal pressure chamber. In one example, thedistal pressure chamber44 may retain a positive pressure of about 10 psig while theproximal pressure chamber43 is pressurized to a pressure of about 40 psig.

The higher pressure in the proximal pressure chamber relative to the lower pressure in thedistal pressure chamber44 will exert a distal force F1 against theproximal surface38aof the threadedrod36. The pressure differential between thepressure chambers43 and44 will thus provide an assistive distal force F1 to the threaded rod when thedeployment actuator21 is rotated in a first direction that causes the threaded rod to move distally.

When theproximal pressure chamber43 is providing an assistive distal force F1 to the threadedrod36, it preferably will still be necessary to rotate thedeployment actuator21 to effect distal movement of the threaded rod due to the engagement of the threads of the deployment actuator with the threaded rod and the relatively low thread angle (i.e., the threads extend relatively perpendicular to the longitudinal axis of the threaded rod) of the threads of the deployment actuator and those of the threaded rod.

In other embodiments (not shown), higher thread angles may be used. If the thread angle is high enough, it may be possible to effect distal movement of the threadedrod36 and rotational motion of thedeployment actuator21 solely by creating a pressure differential between thepressure chambers43 and44, without a user needing to rotate the deployment actuator manually. In some embodiments (not shown), the threaded coupling between the threadedrod36 and thedeployment actuator21 may be replaced with another mechanical feature or a friction fit between the rod and the deployment actuator. For example, the threaded rod and internally threaded deployment actuator can be replaced with a toothed rack and a pinion knob, respectively.

Thepneumatic switch90 may also be movable to a second position that provides pressurized fluid (e.g., air) from the pressure source to thedistal pressure chamber44, while venting theproximal pressure chamber43 to atmospheric pressure, thereby creating a pressure differential between the distal and proximal pressure chambers. For example, pressurized air can be provided to thedistal pressure chamber44 at a pressure of about 40 psig to about 50 psig, whereas the pressure in theproximal pressure chamber43 can be reduced to atmospheric pressure.

In other examples, any other pressure differential between thedistal pressure chamber44 and theproximal pressure chamber43 may be used. It is not required that theproximal pressure chamber43 be vented to atmospheric pressure when thedistal pressure chamber44 is pressurized, so long as the pressure in the distal pressure chamber exceeds the pressure in the proximal pressure chamber. In one example, theproximal pressure chamber43 may retain a positive pressure of about 10 psig while thedistal pressure chamber44 is pressurized to a pressure of about 40 psig.

The higher pressure in thedistal pressure chamber44 relative to the lower pressure in theproximal pressure chamber43 will exert a proximal force F2 against thedistal surface39aof the threadedrod36. The pressure differential between thepressure chambers43 and44 will thus provide an assistive proximal force F2 to the threaded rod when thedeployment actuator21 is rotated in a second direction that causes the threaded rod to move proximally.

When thedistal pressure chamber44 is providing an assistive proximal force F2 to the threadedrod36, it preferably will still be necessary to rotate thedeployment actuator21 to effect proximal movement of the threaded rod due to the engagement of the threads of the deployment actuator with the threaded rod and the relatively low thread angle (i.e., the threads extend relatively perpendicular to the longitudinal axis of the threaded rod) of the threads of the deployment actuator and those of the threaded rod.

Thepneumatic switch90 may optionally be movable to a third position that vents both the proximal anddistal pressure chambers43,44 to atmospheric pressure. In this position, there is no pressure differential between the proximal anddistal pressure chambers43,44, so no assistive proximal or distal force is provided to the threaded rod. This third position may be used when a user wishes to turn off the force-assist feature of thepiston assembly40.

The operating handle20 may also include a resheathing lock mechanism (not shown) as described, for example, in co-pending U.S. patent application Ser. No. 13/788,820, filed Mar. 7, 2013, the disclosure of which is hereby incorporated by reference herein, for preventing the user from accidentally completing the deployment of a valve located in thecompartment23. Such a resheathing lock may limit the longitudinal movement of the threadedrod36 within thehandle housing30.

The operation of the present invention to deploy a prosthetic valve will now be described. To load thedelivery device10 with a collapsible prosthetic valve, the user may pressurize theproximal pressure chamber43 and rotate thedeployment actuator21 in a first direction to move the threadedrod36 distally, and with it theinner shaft26, thereby advancing thedistal sheath24 and exposing thecompartment23. A compressed or crimped valve may then be loaded around thesupport shaft19, and retention members on the distal end of the valve may be coupled to therecesses80 in theretainer25. The user may then pressurize thedistal pressure chamber44 while venting theproximal pressure chamber43, and may rotate thedeployment actuator21 in a second direction opposite the first direction to move the threadedrod36 proximally, and with it theinner shaft26, thereby retracting thedistal sheath24 over the compartment to hold the valve in the compressed state. In this starting condition, thehandle20 will be in an initial state with the threadedrod36 at its proximalmost position within theenlarged bore35.

To use the operating handle20 to deploy a prosthetic valve that has been loaded into thecompartment23 and covered by thedistal sheath24, the user may pressurize theproximal pressure chamber43 and rotate thedeployment actuator21 in the first direction to move the threadedrod36 and theinner shaft26 distally within theenlarged bore35, which thereby pushes the distal sheath distally relative to the compartment and exposes and initiates deployment of the valve located therein. After movement of thedistal sheath24 has partially revealed thecompartment23, the user may continue the deployment process by continuing to rotate thedeployment actuator21 to move the threadedrod36 and theinner shaft26 further distally, which is still being assisted by the pressurizedproximal pressure chamber43.

While theouter sheath24 is uncovering thecompartment23 to expand the prosthetic valve therein, the user can evaluate the position of the valve relative to the patient's aortic annulus and may be able to determine whether the valve is functioning properly. If repositioning or removal is desired before the valve is fully uncovered, the user may resheathe the valve by pressurizing thedistal pressure chamber44 while venting theproximal pressure chamber43, and rotating thedeployment actuator21 in the direction opposite that used for deployment. Such rotation and a proximal force assist from the distal pressure chamber will cause the threadedrod36 to progress proximally through thedeployment actuator21 until the threaded rod has reached the starting position shown inFIG. 2A, thereby recollapsing the expanded part of the valve as thedistal sheath24 is moved proximally over thecompartment23. With the valve resheathed, the user may reposition thedelivery device10 and may commence the deployment procedure once again or may simply remove the valve from the patient.

Although not shown in the figures, it will be appreciated that thedevice10 may include a resheathing lock as described, for example, in co-pending U.S. patent application Ser. No. 13/788,820, filed Mar. 7, 2013, or other structures for selectively limiting the movement of the threadedrod36 within the handle housing. The resheathing lock of thedevice10 will limit the movement of the threadedrod36 distally within the housing to prevent the user from completing the deployment of a prosthetic valve unintentionally.

Once the proper positioning of the valve relative to the aortic annulus has been assured, the user may complete the deployment process. The deployment operation may be completed by continuing to translate the threadedrod36 distally by rotating thedeployment actuator21 with a distal force assist from theproximal pressure chamber43 until the valve is fully uncovered. When the valve has been completely unsheathed, the stent portion of the valve self-expands and disengages from theretainer25, thereby releasing the valve from thecatheter assembly16.

In a variation of thedevice10, the operatinghandle20 may be provided with only a single pressure chamber. Typically, the highest force encountered by a user while rotating thedeployment actuator21 is during resheathing of a partially-deployed prosthetic valve. In thetransapical device10, a proximal force assist F2 can be provided by thedistal pressure chamber44 to the threadedrod36 during rotation of thedeployment actuator21 to translate the threaded rod in a proximal direction during resehathing. In thisdevice10, theproximal pressure chamber43 can be omitted, such that no distal force assist F1 is provided during rotation of thedeployment actuator21 to translate the threaded rod in a distal direction.

Referring now toFIGS. 3A and 3B, an exemplarytransfemoral delivery device110 for a collapsible prosthetic heart valve (or other types of self-expanding collapsible stents) has a catheter assembly116 for delivering the heart valve to and deploying the heart valve at a target location, and anoperating handle120 for controlling deployment of the valve from the catheter assembly. Thedelivery device110 extends from aproximal end112 to anatraumatic tip114 at the distal end of the catheter assembly116. Theatraumatic tip114 may be formed from or may include a radiopaque material to enable the tip to be visible under fluoroscopy during a deployment procedure. The catheter assembly116 is adapted to receive a collapsible prosthetic heart valve (not shown) in acompartment123 defined between aninner shaft126 and adistal sheath124.

Theinner shaft126 may extend through the operating handle120 to theatraumatic tip114 of the delivery device, and includes aretainer125 affixed thereto at a spaced distance fromtip114 and adapted to hold a collapsible prosthetic valve in thecompartment123. Theinner shaft126 may be made of a flexible material such as braided polyimide or polyetheretherketone (PEEK), for example. Using a material such as PEEK may improve the resistance of theinner shaft126 to kinking while the catheter assembly116 is tracking through the vasculature of a patient. Theretainer125 may haverecesses180 therein that are adapted to hold corresponding retention members of the valve.

Thedistal sheath124 surrounds theinner shaft126 and is slidable relative to the inner shaft such that it can selectively cover or uncover thecompartment123. Thedistal sheath124 is affixed at its proximal end to anouter shaft122, the proximal end of which is connected to theoperating handle120 in a manner to be described. Thedistal end127 of thedistal sheath124 abuts theatraumatic tip114 when the distal sheath is fully covering thecompartment123, and is spaced apart from the atraumatic tip when the compartment is at least partially uncovered.

Theoperating handle120 is adapted to control deployment of a prosthetic valve located in thecompartment123 by permitting a user to selectively slide theouter shaft122 and the attacheddistal sheath124 proximally or distally relative to theinner shaft126, thereby respectively uncovering or covering the compartment with the distal sheath. Theouter shaft122 may be made of a flexible material such as nylon 11 ornylon 12, and it may have a round braid construction (i.e., round cross-section fibers braided together) or flat braid construction (i.e., rectangular cross-section fibers braided together), for example.

The proximal end of theinner shaft126 may be connected in substantially fixed relationship to anouter housing130 of theoperating handle120, and the proximal end of theouter shaft122 may be affixed to a threadedrod136 that is translatable along a longitudinal axis of the handle housing. This structure enables a user to selectively slide theouter shaft122 relative to theinner shaft126 by translating the threadedrod136 relative to thehousing130. A hemostasis valve (not shown) may include an internal gasket adapted to create a seal between theinner shaft126 and the proximal end of theouter shaft122. The threadedrod136 has an unthreadedproximal end138 with anend surface138a, and an unthreadeddistal end139 with anend surface139a. Similar to the threadedrod36, the threadedrod136 preferably is longer than the anticipated maximum travel distance of thedistal sheath124.

Thehandle housing130 may include a top portion and a bottom portion. The top portion and bottom portion may be similar to the top andbottom portions30aand30bdescribed above. Thehandle housing130 defines anelongated space134 along the longitudinal axis of the housing in which a piston assembly140 including the threadedrod136 and proximal anddistal piston cylinders141 and142 (described below) may be disposed.

Thehandle housing130 further defines apocket137 that extends transversely through thehousing130 for receiving adeployment actuator121. Thedeployment actuator121 is internally threaded and is in threaded engagement with the threadedrod136. Thepocket137 is sized and shaped to receive thedeployment actuator121 with minimal clearance, such that the location of the deployment actuator remains substantially fixed relative to thehousing130 as it is rotated about the threadedrod136. Rotation of thedeployment actuator121 produces linear movement of the threadedrod136 in the same way as described above with reference to thedeployment actuator21 and the threadedrod36.

The proximal anddistal piston cylinders141 and142 together define anenlarged bore135 that is sized to slidingly receive the threadedrod136. Theenlarged bore135 has an inner diameter slightly larger than the outer diameter of the threadedrod136. Theenlarged bore135 preferably permits the threadedrod136 to travel a distance that is at least as long as the anticipated length of the prosthetic valve to be delivered (e.g., at least about 50 mm), such that thedistal sheath124 can be fully retracted from around the prosthetic valve.

Each of the proximal anddistal piston cylinders141,142 includes arespective pressure chamber143,144 within a portion of theenlarged bore135. The configuration of the proximal anddistal pressure chambers143 and144 and the structure with which the pressure chambers may provide an assistive distal force F1 or an assistive proximal force F2 to the threadedrod136 may be the same as described above with respect to the proximal anddistal pressure chambers43 and44 and the threadedrod36.

Theoperating handle120 may also include a resheathing lock mechanism (not shown) for preventing the user from accidentally completing the deployment of a valve located in thecompartment123, as described above with reference to theoperating handle20.

The operation of the operating handle120 to deploy a prosthetic valve from thecompartment123 is similar to the operation of the operating handle20 of thedevice10 described above. The user can pressurize thedistal pressure chamber144 and rotate thedeployment actuator121 in a first direction to translate the threadedrod136 proximally within theenlarged bore135, and with it theouter shaft122, which thereby retracts thedistal sheath124 proximally from thecompartment123 and exposes and initiates deployment of the valve located therein.

After movement of thedistal sheath124 has partially revealed thecompartment123, the user may continue the deployment process by continuing to rotate thedeployment actuator121 with a proximal force assist from thedistal pressure chamber144, moving the threadedrod136 further proximally within theenlarged bore135, and moving theouter shaft122 and the distal sheath further proximally.

If the user desires to resheathe and reposition the valve or remove the valve from the patient before full deployment, the user can do so by pressurizing theproximal pressure chamber143 while venting thedistal pressure chamber144, and rotating thedeployment actuator121 in the direction opposite that used for deployment. Such rotation and a distal force assist from theproximal pressure chamber143 will cause the threadedrod136 to progress distally through thedeployment actuator121 until the threaded rod has reached the starting position, thereby recollapsing the expanded part of the valve as thedistal sheath124 is moved distally over thecompartment123. With the valve resheathed, the user may reposition thedelivery device110 and commence the deployment procedure once again or can remove the valve from the patient.

Although not shown in the figures, it will be appreciated that thedevice110 may include a resheathing lock as described, for example, in co-pending U.S. patent application Ser. No. 13/788,820, filed Mar. 7, 2013, or other structures for selectively limiting the movement of the threadedrod136 within the handle housing.

Once the proper positioning of the valve has been assured, the deployment operation may be completed by continuing to translate the threadedrod136 proximally by rotating thedeployment actuator121 with a proximal force assist from thedistal pressure chamber144 until the valve is fully deployed.

In a variation of thedevice110, the operating handle120 may be provided with only a single pressure chamber. Typically, the highest force encountered by a user while rotating thedeployment actuator121 is during resheathing of a partially-deployed prosthetic valve. In thetransfemoral device110, a distal force assist F1 can be provided by theproximal pressure chamber143 to the threadedrod136 during rotation of thedeployment actuator121 to translate the threaded rod in a distal direction during resehathing. In thisdevice110, thedistal pressure chamber144 can be omitted, such that no proximal force assist F2 is provided during rotation of thedeployment actuator121 to translate the threaded rod in a proximal direction to deploy the valve.

Many modifications to the various features of the delivery devices described herein are possible. For example, referring toFIGS. 4A-4D, either of thedevices10 or110 may include acoupling assembly60 to selectively place thedeployment actuator21 or121 in threaded engagement with the threadedrod36 or136. Rotational motion of the deployment actuator is only converted into linear motion of the threaded rod when thecoupling assembly60 engages the deployment actuator with the threaded rod.

The ability of thecoupling assembly60 to translate rotation of thedeployment actuator221 into translation of the threadedrod236 relative to thehousing30 or130 may provide the user with the ability to carefully control movement of the threaded rod both proximally within the enlarged bore35 during a valve deployment operation, and distally during a resheathing operation (for the transapical device10), or both distally within theenlarged bore135 during a valve deployment operation, and proximally during a resheathing operation (for the transfemoral device110). The ability of thecoupling assembly60 to decouple thedeployment actuator221 from the threadedrod236 so that the carriage assembly can freely move longitudinally relative to thehousing30 or130 enables gross movement of the threaded rod proximally or distally within the enlarged bore without the mechanical advantage provided by the deployment actuator.

Such gross movement of the threadedrod236 can be provided by either: (1) the user actuating thepneumatic switch90 to either pressurize theproximal pressure chamber43 or143 to move the threaded rod distally or to pressurize thedistal pressure chamber44 or144 to move the threaded rod proximally; or (2) the user manually sliding the threadedrod236 proximally or distally by grasping and sliding a tab or button fixedly coupled to the threaded rod (an example of such a tab or button is shown in the aforementioned U.S. patent application Ser. No. 13/788,820).

Thecoupling assembly60 may be integrated into either thehandle20 or thehandle120 described above by replacing thedeployment actuator21 or121 with thedeployment actuator221 and by separating the proximal anddistal piston cylinders41,42 or141,142 from one another along the longitudinal axis of the handle to create enough room to accommodate the coupling assembly. The threadedrod236 may need to be longer than the threadedrod36 or136 to accommodate thecoupling assembly60 thereon while still providing sufficient travel distance to completely deploy a prosthetic valve.

Thecoupling assembly60 may include asplit nut64 mounted within thedeployment actuator221 through an open side thereof. Thesplit nut64 has first andsecond nut portions64aand64bthat are internally threaded to mate with the threadedrod236. Eachnut portion64aand64bhas a pair of spaced tabs projecting therefrom, with each tab having anaperture65 sized to receive apin76.

Anut ramp66 may be mounted within thedeployment actuator221 adjacent thesplit nut64. Thenut ramp66 has anannular body66awith a pair ofcam arms67 projecting proximally therefrom and slidably positioned between the spaced tabs onrespective nut portions64aand64b. Eachcam arm67 has anelongated cam slot68 sized to slidably receive thepin76 therein.

Aretention ring74 may be press fit into the open side of thedeployment actuator221. A plurality of ribs on the outer periphery of theretention ring74 may mate with a plurality of recesses formed on the inner surface of thedeployment actuator221 to prevent the retention ring from rotating relative to the deployment actuator. Theretention ring74 may include a pair of spacedflanges74athat cooperate with similar spaced flanges formed on the interior of thedeployment actuator221 to sandwich the generally rectangular outer periphery of thesplit nut64 in an assembled position. A largecentral aperture74bin theretention ring74 is sized to slidably receive theannular body66aof thenut ramp66 therethrough. Theretention ring74 further includes a pair of diametricallyopposed slots74cthat are sized and positioned to receive thecam arms67 of thenut ramp66 as theannular body66athereof travels through theaperture74bin the retention ring.

Aring62 may be positioned adjacent theretention ring74 and may be coupled to thenut ramp66 by aflanged fastening ring70 that fits through thering62 and snaps into the nut ramp with an interference fit. The connection between thefastening ring70 and thenut ramp66 is such that thering62 has some freedom of movement between theannular body66aof the nut ramp and the flange of the fastening ring. Anaperture70aextending longitudinally through thefastening ring70 has a diameter that is larger than the diameter of the threadedrod236 so that the threaded rod can slide smoothly and freely therethrough. Acompression spring72, the purpose of which will be described below, may be mounted in the annular space between thefastening ring70 and thering62 and may be constrained longitudinally between theannular body66aof thenut ramp66 and an annular flange formed on thering62.

A pair ofbuttons61 positioned on opposite lateral sides of thering62 may be slidably received in longitudinal openings (not shown) formed on opposite lateral sides of thehousing30 or130. Movement of thebuttons61 to a proximal position in the openings will cause thering62 and, hence, thenut ramp66 to move proximally relative to thesplit nut64, and movement of thebuttons61 to a distal position in the openings will cause thering62 and thenut ring66 to move distally relative to the split nut.

Thering62 further includes anarm63 that extends distally from an outer periphery of the ring. Thearm63 is sized to reside between a pair of posts (not shown) that may project upwardly from the bottom housing portion. The free end of thearm63 includes a pair ofnubs63athat project therefrom in opposite lateral directions. When thebuttons61 are moved to a distalmost position in the housing openings, thenubs63awill be positioned on a distal side of the posts, locking thering62 in this position. When thebuttons61 are moved to a proximalmost position in the housing openings, thenubs63awill be positioned on the proximal side of the posts, locking the ring in this position. As thebuttons61 are moved between the proximalmost and distalmost positions, thenubs63awill deflect the posts slightly outward as they move between the posts.

The first andsecond nut portions64aand64bhave freedom of motion to slide in a substantially perpendicular direction towards or away from the threadedrod236, but they are constrained from longitudinal movement relative to the threaded rod by the sandwiching effect of theinner flanges21aof thedeployment actuator221 and theretention ring flanges74a. Thus, in the assembly described above, thecam slots68 are adapted to translate movement of thenut ramp66 along the longitudinal axis into lateral movement of the first andsecond nut portions64aand64btowards or away from the threadedrod236.

For example, when thebuttons61 are moved to the proximal ends of the respective housing openings, thepins76 will be disposed at the distal ends of thecam slots68, which are located closest to the threadedrod236 in a direction perpendicular to the longitudinal axis. In this position, thenut portions64aand64bwill be in threaded engagement with the threadedrod236. When thebuttons61 are moved to the distal ends of the respective housing openings, thepins76 will be disposed at the proximal ends of thecam slots68, which are located farthest from the threadedrod236 in the direction perpendicular to the longitudinal axis. In this position, thenut portions64aand64bwill be disengaged from the threadedrod236. Therefore, when a user slides thebuttons61 proximally, rotation of thedeployment actuator221 translates the threadedrod236, and when the user slides the buttons distally, the deployment actuator becomes decoupled from the threaded rod.

When the user slides thebuttons61 proximally to move thenut portions64aand64btoward the threadedrod236, interference between the threads on the nut portions and the threads on the threaded rod may prevent complete threaded engagement between thesplit nut64 and the threaded rod. Nonetheless, thering62 will move to its proximalmost position so that thenubs63asnap into place on the proximal side of the posts. With the aforementioned interference preventing thenut portions64aand64bfrom continuing into full threaded engagement with the threadedrod236, and thus preventing thenut ramp66 from further movement proximally, the last portion of the movement of thering62 in the proximal direction will cause thespring72 to compress. This compression will add an extra lateral force to thenut ramp66. Accordingly, as thedeployment actuator221 is rotated, the threads of thenut portions64aand64bwill properly align with the threads of threadedrod236 and the biasing force exerted by thespring72 on thenut ramp66 will assure that the nut portions become fully engaged with the threaded rod.

In another variation, referring toFIGS. 5A-5D, either of thedevices10 or110 may replace thedeployment actuator21 or121 and thepneumatic switch90 with asmart wheel assembly300, which is adapted to combine the control of both the sliding of the threaded rod and the provision of pressurized fluid to the proximal and distal pressure chambers in a single assembly. Similar to thecoupling assembly60, thesmart wheel assembly300 may be integrated into either thehandle20 or thehandle120 described above by separating the proximal anddistal piston cylinders41,42 or141,142 from one another along the longitudinal axis of the handle to create enough room to accommodate the smart wheel assembly.

Thesmart wheel assembly300 includes adeployment actuator321 and atoggle guide390. Thetoggle guide390 is adapted to translate in a longitudinal direction of the operating handle in response to rotation of thedeployment actuator321, thereby actuating a pneumatic switch (not shown) that provides pressurized fluid to either the proximal or distal pressure chamber, depending on the position of the toggle guide. For example, thesmart wheel assembly300 has a contracted condition with a width W1 when thetoggle guide390 is disposed immediately adjacent thedeployment actuator321, as shown inFIG. 5B. In this contracted condition, the distal pressure chamber may be pressurized. Thesmart wheel assembly300 also has an expanded condition with a width W2 when the toggle guide is remote from the deployment actuator (position390′ inFIG. 5B). In this expanded condition, the proximal pressure chamber may be pressurized.

Thedeployment actuator321 is internally threaded, and when assembled into thehandle20 or120, is in threaded engagement with the threadedrod36 or136. Thetoggle guide390 has aninner bore350 that is adapted to slidably receive the threadedrod36 or136 therethrough.

The substantially flat face of thedeployment actuator321 facing thetoggle guide390 has anouter ratchet surface322 in the form of a ring extending around the outer circumference of the surface, and aninner ratchet surface323 in the form of a ring disposed radially inward of the outer ratchet surface. Theouter ratchet surface322 and theinner ratchet surface323 each have a plurality ofteeth324. Theteeth324 of theouter ratchet surface322 are angled in the opposite direction of those of theinner ratchet surface323.

Thesmart wheel assembly300 has anouter cylinder332 disposed radially inside thetoggle guide390, the outer cylinder having a ratchet surface formed by a plurality ofteeth334 facing theouter ratchet surface322 of thedeployment actuator321. Thesmart wheel assembly300 also has aninner cylinder333 disposed radially inside theouter cylinder332, the inner cylinder having a ratchet surface formed by a plurality ofteeth334 facing theinner ratchet surface323 of thedeployment actuator321. Theteeth334 of theouter cylinder332 are angled in the opposite direction of those of theinner ratchet333 cylinder.

Theouter cylinder332 is arranged such that itsteeth334 confront and are adapted to mesh with theteeth324 of theouter ratchet surface322 when thedeployment actuator321 is rotated in a first direction R1 (FIG. 5C), such that when engaged with one another, rotation of the deployment actuator in the first direction causes the outer cylinder to rotate therewith, while rotation of the deployment actuator in a second direction R2 opposite the first direction does not rotate the outer cylinder.

Theinner cylinder333 is arranged such that itsteeth334 confront and are adapted to mesh with theteeth324 of theinner ratchet surface323 when thedeployment actuator321 is rotated in the second direction R2, such that when engaged with one another, rotation of the deployment actuator in the second direction causes the inner cylinder to rotate therewith, while rotation of the deployment actuator in the first direction R1 does not rotate the inner cylinder.

Thesmart wheel assembly300 has anouter spring342 extending between theouter cylinder332 and aninner end surface391 of thetoggle guide390, and aninner spring343 extending between theinner cylinder333 and the inner end surface of the toggle guide. Thesprings342 and343 are always under compression, such that their biasing force will tend to urge thetoggle guide390 away from thedeployment actuator321, thereby urging thesmart wheel assembly300 toward the expanded condition. Thetoggle guide390 hasseparation fins355 that are adapted to maintain the positions of theratchet cylinders332,333 and thesprings342,343 relative to thedeployment actuator321 as thesmart wheel assembly300 moves between the contracted and expanded conditions.

Thetoggle guide390 has aguide slot360 disposed in theinner separation fin355. Theguide slot360 has afirst end361 adjacent thedeployment actuator321 and asecond end362 remote from the deployment actuator. Thesecond end362 of theguide slot360 has aledge portion363 extending substantially perpendicularly to a longitudinal axis L of thesmart wheel assembly300. Theguide slot360 is sized to accommodate apin365 extending radially inward from an inner surface of theinner cylinder333. Theguide slot360 and thepin365 are configured so that thetoggle guide390 can move along the longitudinal axis L a distance T (FIG. 5B) as thepin365 moves between the first and second ends361,362 of the guide slot.

Theguide slot360 and thepin365 are configured such that, when thedeployment actuator321 is at rest and the pin is disposed adjacent the first end of361 of theguide slot360, the biasing force of thesprings342,343 will keep thetoggle guide390 at theposition390′ (FIG. 5B), with the smart wheel assembly being in the expanded condition with a width W2. When thedeployment actuator321 is rotated in the second direction R2, which also rotates theinner cylinder333 in the second direction, thepin365 will move along theguide slot360 to thesecond end362 and onto theledge portion363 of the guide slot, thereby further compressing thesprings342,343 and disposing thetoggle guide390 adjacent thedeployment actuator321 as shown inFIG. 5B, such that the smart wheel assembly is in the contracted condition with a width W1 smaller than the width W2.

Theguide slot360 and thepin365 are also configured such that, whendeployment actuator321 is at rest and thepin365 is disposed at thesecond end362 of theguide slot360, friction between the pin and theledge portion363 of the guide slot will be sufficient to prevent the biasing force of thesprings342,343 from pushing thetoggle guide390 back to theposition390′. When thedeployment actuator321 is rotated in the first direction R1, there will be friction between theinner cylinder333 and the deployment actuator as the opposing teeth slip past one another, and this friction force will slightly rotate the inner cylinder relative to the toggle guide to a degree that is sufficient to overcome the friction between thepin365 and theledge portion363 of theguide slot360, so that the biasing force of thesprings342,343 will move thetoggle guide390 to theposition390′, such that the smart wheel assembly is disposed in the expanded condition.

In use with thetransapical delivery device10, for example, when thesmart wheel assembly300 is at rest with thepin365 at thefirst end361 of theguide slot360, the smart wheel assembly will be disposed in the expanded condition with the toggle guide remote from the deployment actuator (position390′) and theproximal pressure chamber43 may be pressurized, thereby providing a distal force to the threadedrod36.

When a user desires to begin advancing thedistal sheath24 distally to begin deployment of a prosthetic valve, the user may rotate thedeployment actuator321 in the first direction R1, which will rotate theouter cylinder332 therewith in the first direction R1, and which will move the threadedrod36 distally through theinner bore350 of thetoggle guide390 with a distal pressure assisting force from the pressurizedproximal pressure chamber43. Thetoggle guide390 and theinner cylinder333 will not rotate with the deployment actuator, because theteeth334 of the inner cylinder are not engaged with theteeth324 of thedeployment actuator321.

If a user desires to retract thedistal sheath24 proximally to resheathe the prosthetic valve, the user may begin to rotate thedeployment actuator321 in the second direction R2, which will rotate theinner cylinder333 therewith in the second direction R2, thereby sliding thepin365 along theguide slot360 to thesecond end362 and onto theledge portion363 of the guide slot, drawing thetoggle guide390 toward thedeployment actuator321 while further compressing thesprings342,343 as shown inFIG. 5B, such that the smart wheel assembly is disposed in the contracted condition.

During this movement of thepin365 from thefirst end361 to thesecond end362 of theguide slot360, which may be during approximately 1/10 of a full rotation of thedeployment actuator321 in the second direction R2, thetoggle guide390 and theouter cylinder333 will not rotate with the deployment actuator, because theteeth334 of the outer cylinder are not engaged with theteeth324 of the deployment actuator.

When thetoggle guide390 moves adjacent thedeployment actuator321, a pneumatic switch (not shown) is actuated so that pressurized fluid is provided to thedistal pressure chamber44, while theproximal pressure chamber43 is vented to atmospheric pressure, thereby providing a proximal force to the threadedrod36.

When the user continues to rotate the deployment actuator in the second direction R2 with thepin365 at thesecond end362 of theguide slot360, the resulting continued rotation of theinner cylinder333 will rotate thetoggle guide390 therewith by way of the pin providing a rotating force to the second end of the guide slot. Also, the continued rotation of thedeployment actuator321 in the second direction R2 will move the threadedrod36 proximally through theinner bore350 of thetoggle guide390 with a proximal assisting force from the pressurizeddistal pressure chamber44.

If a user desires to resume advancing thedistal sheath24, the user may rotate thedeployment actuator321 in the first direction R1, which will rotate theouter cylinder332 therewith in the first direction R1. Although thetoggle guide390 and theinner cylinder333 will not fully rotate with the deployment actuator, because theteeth334 of the inner cylinder are not engaged with theteeth324 of thedeployment actuator321, there will be some friction between theteeth334 of the inner cylinder and theteeth324 of the deployment actuator as the opposing teeth slip past one another, and this friction force will slightly rotate the inner cylinder relative to the toggle guide to a degree that is sufficient to overcome the friction between thepin365 and theledge portion363 of theguide slot360, so that the biasing force of thesprings342,343 will dispose thetoggle guide390 at theposition390′ (FIG. 5B) with thepin365 again adjacent thefirst end361 of theguide slot360, such that the smart wheel assembly is disposed in the expanded condition.

When thetoggle guide390 moves to theposition390′ remote from thedeployment actuator321, the pneumatic switch (not shown) is again actuated so that pressurized fluid is provided to theproximal pressure chamber43, while thedistal pressure chamber44 is vented to atmospheric pressure, thereby providing a distal force to the threadedrod36, which will permit the user to resume advancing thedistal sheath24 by rotating the deployment actuator in the first direction R1 with a distal pressure assisting force from the pressurized proximal pressure chamber.

The operating handles described herein may be provided with a deployment locking mechanism. Such a deployment locking mechanism may prevent the accidental initiation of deployment by fixing the threadedrod36 or136 to the handle housing while the lock is in a locked position. Such a deployment lock may have a structure similar to the deployment locks shown and described in co-pending U.S. patent application Ser. No. 13/212,442, filed Aug. 18, 2011, the disclosure of which is hereby incorporated by reference herein.

Although the operating handles described herein are described as having a piston in the form of a threadedrod36,136, or236, the piston may take other forms. For example, the threaded rod and internally threaded deployment actuator can be replaced with a toothed rack and a pinion knob, respectively. In such an embodiment, the toothed rack may extend into the enlarged bore of the piston cylinders, and it may be sealed against inner surfaces of the piston cylinders by proximal and distal seals, thereby creating proximal and distal pressure chambers extending between the inner surface of each piston cylinder and the seals of the toothed rack.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It will be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.

Claims (8)

The invention claimed is:

1. A delivery device for a collapsible prosthetic heart valve, the delivery device comprising:

an operating handle, including:

a housing defining a movement space therein;

a piston cylinder disposed within the movement space;

a piston slidable in a longitudinal direction within the piston cylinder, the piston and the piston cylinder together defining at least one pressure chamber;

a deployment actuator coupled to the housing and rotatable relative to the housing; and

a pneumatic switch in fluid communication with the pressure chamber, the pneumatic switch adapted to provide a pressurized fluid to the pressure chamber to apply a force to the piston in the longitudinal direction; and

a catheter assembly, including:

a first shaft around which a compartment is defined, the first shaft being operatively connected to the housing, the compartment being adapted to receive the valve in an assembled condition; and

a distal sheath operatively connected to the piston, the distal sheath being moveable between a closed condition covering the compartment and an open condition uncovering the compartment for deployment of the valve,

wherein movement of the piston in the longitudinal direction in the piston cylinder moves the distal sheath between the closed condition and the open condition; wherein rotation of the deployment actuator in a first direction actuates the pneumatic switch and provides the pressurized fluid to the pressure chamber; and wherein the operating handle further includes a toggle guide moveable in the longitudinal direction relative to the deployment actuator, and rotation of the deployment actuator in the first direction causes movement of the toggle guide in the longitudinal direction away from the deployment actuator, thereby actuating the pneumatic switch.

2. The delivery device ofclaim 1, wherein the piston cylinder includes a proximal piston cylinder and a distal piston cylinder, the piston and the proximal piston cylinder together defining a proximal pressure chamber and the piston and the distal piston cylinder together defining a distal pressure chamber.

3. The delivery device ofclaim 1, wherein the first shaft is attached to the distal sheath and operatively connected to the piston, the catheter assembly further including an outer shaft connecting the housing to the compartment and at least partially surrounding the first shaft, and wherein the piston cylinder is a distal piston cylinder surrounding a distal end of the piston.

4. The delivery device ofclaim 1, wherein the catheter assembly further includes an outer shaft attached to the distal sheath and operatively connected to the piston, the outer shaft at least partially surrounding the first shaft, wherein the piston cylinder is a proximal piston cylinder surrounding a proximal end of the piston.

5. The delivery device ofclaim 1, wherein the deployment actuator is a knob rotatable about a central axis that extends parallel to the longitudinal direction.

6. The delivery device ofclaim 1, wherein rotation of the deployment actuator in a first direction moves the piston proximally in the longitudinal direction, and rotation of the deployment actuator in a second direction opposite the first direction moves the piston distally in the longitudinal direction.

7. The delivery device ofclaim 1, wherein:

the piston cylinder includes a proximal piston cylinder and a distal piston cylinder, the piston and the proximal piston cylinder together defining a proximal pressure chamber and the piston and the distal piston cylinder together defining a distal pressure chamber, and

rotation of the deployment actuator in a first direction actuates the pneumatic switch and provides the pressurized fluid to the proximal pressure chamber, and rotation of the deployment actuator in a second direction opposite the first direction actuates the pneumatic switch and provides the pressurized fluid to the distal pressure chamber.

8. A delivery device for a collapsible prosthetic heart valve, the delivery device comprising: an operating handle, including: a housing defining a movement space therein; a piston cylinder disposed within the movement space; a piston slidable in a longitudinal direction within the piston cylinder, the piston and the piston cylinder together defining at least one pressure chamber; a deployment actuator coupled to the housing and rotatable relative to the housing; and a pneumatic switch in fluid communication with the pressure chamber, the pneumatic switch adapted to provide a pressurized fluid to the pressure chamber to apply a force to the piston in the longitudinal direction; and a catheter assembly, including: a first shaft around which a compartment is defined, the first shaft being operatively connected to the housing, the compartment being adapted to receive the valve in an assembled condition; and a distal sheath operatively connected to the piston, the distal sheath being moveable between a closed condition covering the compartment and an open condition uncovering the compartment for deployment of the valve, wherein movement of the piston in the longitudinal direction in the piston cylinder moves the distal sheath between the closed condition and the open condition; wherein the piston is a threaded rod in threaded engagement with the deployment actuator; wherein the operating handle further includes a coupling assembly rotationally fixed to the deployment actuator, the coupling assembly having an engaged position in which rotation of the deployment actuator moves the threaded rod in the longitudinal direction, and a disengaged position in which rotation of the deployment actuator does not move the threaded rod in the longitudinal direction and wherein the coupling assembly includes a split nut having a plurality of threaded split nut portions, the split nut portions each being linearly slidable away from one another and away from the threaded rod, the split nut having an engaged position in which threads of the split nut portions are engaged with the threaded rod and a disengaged position in which the threads of the split nut portions do not engage the threaded rod.

Images